Oxalis pes-caprae
Oxalidaceae
African wood-sorrel, Bermuda buttercup, soursob
oxalis family, wood-sorrel family
basal, rarely absent at flowering;
petiole 3–12 cm;
leaflets 3, green, rarely mottled with purplish red spots, angular-obcordate, (5–)7–20 mm, lobed 1/4–2/5 length, lobes apically convex, margins and abaxial surface villous, adaxial surface glabrous, oxalate deposits absent.
alternate or whorled, usually palmately or pinnately compound, sometimes 1-foliolate;
stipules usually present, rarely apparently absent;
petiole present;
blade margins entire;
venation pinnate or subpalmate.
umbelliform cymes, 2–12(–20)-flowered;
scapes often becoming fistulose proximally, 15–30 cm, sparsely villous to pilose.
terminal or axillary, cymes or racemes, or flowers solitary.
tristylous in diploids and tetraploids, consistently short-styled in pentaploids;
sepal apices with 2 orange tubercles;
petals deep golden yellow, 15–20 mm.
bisexual, perianth and androecium hypogynous;
hypanthium absent;
sepals 5, distinct or slightly connate basally;
petals 5, distinct or slightly connate basally;
nectary present;
stamens 10 in 2 whorls, connate basally (monadelphous), free;
anthers dehiscing by longitudinal slits;
pistil 1, 5-carpellate, ovary superior, 5-locular;
placentation axile;
ovules (1–)3–8(–10) per locule, anatropous;
styles 5, distinct;
stigmas 5.
capsules [berries], dehiscence loculicidal, often elastically.
not seen.
1–10 per locule.
= 14, 28, 35.
Oxalis pes-caprae
Oxalidaceae
Outside its native range, Oxalis pes-caprae is mostly represented by a sterile pentaploid morph, although tetraploids also are known. The occurrence of both pentaploid and tetraploid individuals in the exotic range may be the result of independent introductions (P. Michael 1964; R. Ornduff 1986). Fruit production has not been observed in North America, and the plants are assumed to be seed-sterile (Ornduff 1987). Bulbs of O. pes-caprae are rarely collected, as they detach easily from the vertical, rootlike stems. Each bulb may produce over 20, small, whitish bulblets each year. Bulblets may also be formed at the soil surface crown.
Oxalis pes-caprae was reported by J. K. Small (1933) to occur in waste places and cultivated grounds in northern Florida, but as noted by D. B. Ward (2004), no Florida specimens are known.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
Genera 5, species ca. 800 (1 genus, 36 species in the flora).
Oxalidaceae occurs mostly in the tropics and subtropics of both hemispheres but extends into temperate regions. Species of Averrhoa Linnaeus and Sarcotheca Blume are trees or shrubs, those of Dapania Korthals lianas; all have fleshy, baccate fruits. Species of Biophytum de Candolle and Oxalis are herbs, subshrubs, shrubs, or rarely vines with capsular fruits; Biophytum has even-pinnate leaves fascicled at the stem tips. Seeds of Oxalidaceae develop an elastic, translucent, arilliform epidermis that turns inside out, explosively ejecting them from the capsule (K. R. Robertson 1975).
Oxalis tuberosa Molina (oca or New Zealand yam), of Andean South America, is cultivated for its edible tubers. Averrhoa is widely cultivated in the tropics for its fruits, which are eaten fresh, used in drinks, or made into jelly and jam. Both species of Averrhoa [A. bilimbi Linnaeus (bilimbi or cucumber tree), A. carambola Linnaeus (starfruit or carambola)] are known only in cultivation or as escapes from cultivation.
(Discussion copyrighted by Flora of North America; reprinted with permission.)
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